Missing Storage
I have lost all of the files I had previously. Under "Show Data Directory", there are no stored files anywhere. When I log into my account on the webpage, my stored files are also gone. Unfortunately, this summer, the motherboard on my computer had to be replaced, but other files (such as Word documents, etc.) were saved. Please advise.
An account isn't required to use Zotero, so it's entirely possible you were just using Zotero locally without syncing. If you have other email addresses, you can try resetting your password with those, but otherwise your data would only have been on the computer where you last used Zotero.
Zotero shows a fairly bold warning if you haven't enabled syncing, but it's entirely optional to set up.